In International Patent Application Publication No. W092/14712, there is disclosed a benzothiazolesulfonylaminoethyl derivative, more specifically, 1- 2-(6-benzothiazolesulfonylamino)ethyl!-4- 3-(phenoxy)propyl!piperazine, which has the ability to relax a bronchial smooth muscle by its antihistaminic activity. However, there is no description teaching or suggesting that the above-mentioned benzothiazolesulfonylaminoethyl derivative has a protein kinase inhibiting activity.